kernel - config

Hi Every One, I am using Linux 2.4 with 8390 Network driver. For configuring rshaper i need to insert the following line in Global space of Kernel. int (*net_shaper_rx_hook)(struct sk_buff *skb) = NULL; Can you suggest me anyone steps to insert the line and where. I am very new to kernel part. I am very greatful to you if any one help me in this regard. Thanks in Advance Tulasi